A known load compartment cover of the mentioned type (DE 10 2008 017 084 B4) is to be used for the purpose of providing an audio system of a vehicle in such a manner that the audio system renders possible a natural audio experience in particular in the range of lower frequencies and to a large extent avoids the formation of standing waves. For this purpose in the case of the known system, a plate is arranged above the load compartment and that plate is embodied from a rigid mesh, preferably a metal mesh of sufficient rigidity and mass. That mesh is provided with a textile, felt-like or also leather or synthetic leather-type cover.
Helmholtz resonators are also known as sound absorbers (Wikipedia Helmholtz resonator) for improving the general acoustics of the compartment. Helmholtz resonators essentially comprise a vibrating mass and a resilient element. The sound energy that occurs is converted into kinetic energy of the mass. The maximum absorption occurs in the range of the resonant frequency where the mass vibrates most intensely. The vibrating mass is the air that is located in the holes. The volume of air is delimited by means of plates embodied from plywood, gypsum, particle board, synthetic leather or also thin sheets. The volume of air that is enclosed behind the plate acts as a resilient element. The advantage of resonance absorbers of this type is their high capacity to absorb sound, in particular in the case of low frequencies that often occur in the passenger compartments of motor vehicles, in particular when using audio systems.
In addition, very effective, multilayer sound-absorbing plates are known (U.S. Pat. No. 8,573,358 B2). Such plates are embodied from micro perforated thin sheets and a wire mesh is present between said plates in order to maintain the spacing between the thin sheets.